Slitter unit assembly



Feb. 23,1943. R, M CQJOHNSTONE ,1 v I SLITTER UNIT ASSEMBLY I Filed Jan. 51, 1942 2 Sheets-Sheet 1 Feb. 23, 1943.

R. M c. JOHNSTONE SLITTER UNIT ASSEMBLY Filed Jan. 31, 1942 2 Sheets-Sheet 2 ter element;

Patented Feb. 23,

, UNITED STATES PATENT OFF-ICE SL'ITTER'UNIT ASSEMBLY Robert McC. Johnstone, Bondsville, Pa. Application'Januar-y 31, 1942, Serial No. 429,087

' (Cl .164---65) I Q I ficlaims. This invention relates to slitting vide a generally improved form of slitter unit.

More specifically, one object of the invention is to provide an improved means for mounting the slitter disk in its supporting levers-said means aifording a substantially sealed disk.

Another specific object is to provide an improved means for attaching to a slitter lever the tensioning spring which constitutes an element of the slitter unit assembly.

Still another object of the invention is to provide a slitter bar assembly wherein the tensioning spring is positioned with respect to the other elements of the lever assembly so as to afiord the lever a relatively high degree of stability in the machine assembly.

The invention further affords a novel fulcruming and spacing device for the levers, as hereinafter setforth.

In the .attached drawings:

T I machines. and a principal object of the invention is to probearing for the Figure 1 is a diagrammatic'sectional view showing parts of a slitting and rewinding machine incorporating my lnventiom. v

Fig. 2 is an enlarged sectional view showing the slitter unit and its mounting;

Fig. 3 is a top plan view of the slitter unit assembly shown in Fig. 2; Fig. 4 is a detached view in perspective of one of the structural elements of the slitter bar assembly;

Rig. 5,-is a section on the line 5-5, Fig. 2;

Fig. 61s alongitudinal sectional view illustrating details of the slitter bar assembly;

Fig. 7 is a detached view in elevation ofa slit- Fig. 8 is a view in perspective of one of the spacer elements, and

Fig. 9 is a top plan view illustrating a plurality of the'slitter bars in a typical gang assemblyin the machine.

Referring to Fig. 1 .of the drawings, the webslitting machine therein illustrated comprises frontand rear winding drums I and 2, a winding shaft'3 and a top pressure roll 4. The web 5. which constitutes the work material, is guided under the drums I and 2 and upwardly around the former to the shaft 3, on which it is wound in well known manner to produce a roll 6. Op,- eratively associated with the-front drum I is one or more slitter elements each in the form, in the present instance, of a disk I, this element'functioning to slit the web against the drum I prior to its'passage to the roll 6.

V The disk I is mounted in one end of a lever l.

This lever is composed, in the present instance. of'two side plates 9, 9, secured against opposite sides of a plate II. The plate Ills not coextensive with'the side plates 9, so that a space I2 is provided between the side plates for reception of the disk 1.. The outer. end of the space I2 is closed by a spacer element I3, which is secured between the extremities of the sideplates 9.

To the opposite end of the plate II is secured a leaf spring I4, the function of which will be hereinafter described. This spring is clamped solidly upon a shoulder I 5 of the plate II by means of a clamp I6. This clamp, as shown in perspective in Fig. 4, consists of a hollow rectanguiar body member the sides of which in assembly embrace and fit snugly against the opposite sides of the spring I4, and also against ,the opposite sides of the plate II, it being noted, by

the clamp I6 is a screw I9 which, in assembly, is

tightened against the under side of the plate II to thereby draw the top of the clamp solidly down upon the base of the spring I4, and to thereby clamp the spring to the plate II, the

hook I! providing apositlve interlock between the clamp and the plate II.

The disk I, see Fig.5, is provided with an antifriction bearing 2 I, and this bearing and the hub portion 22 of the disk are formed to fit neatly between the side plates 9, 9 of the lever 8. The outer face of each of the plates 9 is provided with a slot-like recess 23 and an aperture in the bottom of said recess for reception of a pin 24 which provides a pintle support for the disk I. The pin 24 is formed, as shown in Fig. 5, with a central portion 25 and end portions 26 formed in the present instanceby turning circumferential grooves in the pin body. 'The central portion 25 receives the inner race of the bearing 2|, and the end portions 26 function as heads to retain the pin against axial displacement in the side plates. The apertures in these plates which receive the pin are in thenature of bayonet joints, as indicated in broken lines in Fig. 3, with end portions 21 of diameter sufiiciently large to permit passage therethrough of the portions 25 and 26 of the pin of relatively great diameter. The pertions 23 of smaller size neatly fitting the portions of the pin of relatively small diameter which lie intermediate the end portions 23 and the central portion 25. With the pin established in the smaller ends 28 of the apertures, it is apparent that axialdisplacement of the pin is precluded, and that withdrawal of the pin may be effected only after the pin is moved bodily upwardly into the larger ends 21 of the apertures. It will be noted that in operation, the reaction forces between the disk I and the drum l are in a direction to retain the disk in the smaller ends of the said apertures.

On the under side of the lever 3 is an angular notch 29 which is inset both in the side plates '3 and the spacer plate II. In the machine assembly, this notch 29 receives the knife edge 3| of a fulcrum member 32, this member being in the form, in the present instance, of a bar which is coextensive with the drum As shown in Figs. 2 and 3, the fulcrum bar 32 is substantially rectangular. in form with the knife edge formation 3| projecting from the upper fiat top so as to afford at each longitudinal side thereof a laterally projecting shoulder .33. In the forward side of the bar 32 is a longitudinal notch or recess 34. the function of which will be hereinafter described. v

In conjunction with the aforedescribed slitter lever assembly, I provide a spacer member 35 shown in perspective in Fig. 8. This member has in the base thereof a transverse recess 36 which is shaped to recei e the fulcrum bar 32, as best shown in Fig. 2. It will be noted that the spacer engages the bar 32 only at the sidesthereof and on the shoulders 33, there being no contact between the spacer and the knife edge 3|. In the forwardwall of the recess 33 the spacer member 35 carries a set screw 31 which in assembly is threaded inwardly against the inclined face of the recess 34, the resulting reaction being such as to clamp the spacer element solidly against one side and the shoulders 33 of the fulcrum bar 32, as shown in Fig. 2. The spacer element further comprises two cheeks 33, 33 which occupy positions at opposite sides of the side plates 3 of the lever, and which form therebetween a slotted opening in which the said lever is neatly fitted, as shown in Fig. 5. The spacer element is formed so that normal contact between the element and the lever occurs only on the outer side faces of the side plates 9 and the inner surfaces of the cheeks 33, it being noted that the knife edge 3| of the bar 32 in assembly extends upwardly into the space between the said cheeks for fulcrumin engagement with the lever. Thus while the spacer element functions to positively locate andretain the lever in adjusted position longitudinally of the fulcrum bar, it offers no interference with the free pivotal movement of the lever on' the fulcrum.

In the machine assembly, the fulcrum bar 32 is mounted upon a beam 33 which may be elevated and lowered through the medium of an eccentric 4| on a shaft 42. When the fulcrum bar is thus elevated to bring the disk I into engagement with the platen roll I, the outer free end of the spring H engages the underside of a transverse beam 43, the parts being so related that the spring I4 is placed under tension, as illustrated in Fig. 1. The outer end of the spring I4 carries a screw 44 which may be adjusted in the spring so as to regulate the tension. It is to be noted that the spring l4 extends from the lever body, and that when the lever is in the operative position in the machine, as shown in Fig. 1, a straight line between the axis of the slitter disk I and the point of contact between the screw 44 of the spring I4 and the beam 43 will lie below the bottom of the notch 29 whichreceives the d knife edge 3|, as previously described. By having this line between the axis of the disk I and the point of engagement of th spring I4 with the abutment 43 extend in proximity to the fulcrum axis, the lever is afforded a relatively high degree of stability on the fulcrum with little or no tendency for the lever to turn laterally on the fulcrum.

The use of the knife-edge fulcrum 3| affords a material improvement over the semi-circular or rounded fulcrum conventionally employed in this type of slitter mecianism. The slitter disks 1 are almost invariably slightly irregular or out of round' at the periphery, and at the higher speeds of operation, these slight irregularities have a tendency by reaction with the drum to cause the the recesses, preventing access thereto of dust" disk to jump away from the drum surface with consequent momentary partial release of the slitting pressure. Increase in the slitter tension will compensate for this undesirable action, but only to the extent that the slitter bar has freedom of movement on its fulcrum. Thus the greater the friction loss in the fulcrum, the greater will be the tension required and the lower the degree of compensation. The substantial elimination of friction loss in the fulcrum due to use of the knife edge aflords more efllcient slitting with reduced tension.

It will be noted further with reference to Fig. 5 that the wings 33 of the spacer element 33, which as previously set forth lie closely against the opposed faces of the side plates 9, 9, overlie the recesses 23 in the said plates in which are estab-- lished the head ends of the pin 24. The wings 33, 33 thereby function in effect to close or seal or lint which otherwisemight find its way to the-bearings 2|. Similarly the close flt between the side plates 3 and the hub 22 of the disk I tends to prevent passage of dust'and dirt to the bearings between the disk and the plates. In some instances, 'as shown in Fig. 9, a lever may be mounted on the fulcrum bar between two ad- Joining, spacers 35,-or in direct contact with another of the levers. Contact between the sides of the lever and the outer faces of the wings 33 of the spacers effects the bearing seal described above; and direct contact between the side faces of two immediately adjoining levers affords a mutual sealing effect.

Iclaim:

1. In a slitter lever assembly, spaced side plates having aligned apertures terminating respectively in recesses in the outer faces of the plates, said apertures being in the form of slots having enlarged portions, a pin neatly fitting the relatively small portions of the apertures and having enlarged heads at the ends thereof together with an enlarged mid portion insertable in the apertures through the said enlarged portions of the latter, said heads being confined to the said recesses entirely inside of the planes of the outer faces of th plates, and a slitter disk closely fitted between the plates and mounted on the said mid portion of the pin.

2. In a slitter unit of the type described, a {lever having a rotary slitter disc at one end, a tensioning spring at the other end, and means body of the lever 3 substantially in line with the 73 for establishing a fulcrum at a point intermedlate the spring and the disc, the axis of the disc, the outer end of the spring and the inicruming means being relatively disposed so that after flexure of the spring. as in normal operation, a straight line intersecting the axis of the disk and the said spring end will lie substantially on or beyond the fulcrum point in the direction of said flexure.

3. In a slitter unit of the type described. a lever having a rotary slitter disc at on end, a tensionin-g spring at the other end, a fulcrumreceiving socket intermediate said disc and spring, the axis of the disc, the socket and the outer terminal end of the spring being in approximate alignment so that when the spring is flexed as in normal operation a straight line intersecting the axisof the disc and the said spring end will also intersect the said socket.

4. In a slitter unit of the type comprising a lever, a slitter element mounted in the lever, a leaf spring, and means for securing the spring to the lever; a seat on the lever for the spring, a clamp embracing and fitting closely against the sides of the lever and the spring around the seat, means on the clamp operative byreaction with the lever to draw the spring forcibly againstthe seat, and means for positively interlocking the clamp with the lever.

5. In a slitter assembly of the type comprising .a lever having a fulcrum-receiving socket, a slitter element at one side of the socket, and, a tensioning spring at the other side of the socket: a fulcrum bar of generally rectangular cross sectional form, said bar having a knife edge pro- Jecting from the top surface thereof for engageinent in the said lever socket and a flat shoulder at each side of said knife edge, an inwardly and downwardly inclined surface forming one face of a longitudinal notch in one side face of the bar.

and a spacer element-having a recess for recep tion of said bar andseating solely against one side of the bar and said shoulders, said spacer having a slot-like opening in the top for reception of the lever, and a clampingscrew in one side arranged substantially normal to and for engagement with the said inclined surface of the bar.

6. In a slitter assembly of the type comprising a lever having a fulcrum-receiving socket, a slitter disk at one side of the socket, and a spring at the othenside of the socket for resiliently retaining the disk in engagement with a relatively movable platen; a bar forming a pivotal support for the lever and having a knife edge for engagement as a fulcrum in said socket.

' ROBERT McC. JOHNSTONE. 

